Characteristics of dual-reflex camera

In traditional cameras, one is used for framing and the other is used for imaging. However, lenses are generally not replaceable. If the two lenses are not replaced together, the parallax between the viewfinder and the imaging lens will be great.

One of the characteristics of dual-lens camera imaging is that the image seen in the viewfinder lens is often different from the image recorded by the imaging lens on the film, and there is parallax. Also, framing is very troublesome and it is difficult to focus. You must start a magnifying glass to check your vision. If used well, it is similar to SLR camera imaging. In addition, the double-reflex camera can alleviate the unnatural performance of the subject when shooting because the photographer bows his head when taking pictures.

In addition, compared with SLR, TLR has an extra lens for framing, and the reflector is fixed, which does not affect framing when taking photos (SLR cameras cover the framing screen because the reflector is raised, so they can't see the image when exposed). The image size on the ground glass is exactly the same as that on the film. However, the structure of TLR system also determines that it has the following problems: 1. Because the viewfinder lens and the photographic lens are separated, TLR has parallax problem (that is, what you see is what you get) like the paraxial viewfinder camera. The disadvantages of this problem will be more obvious when shooting close-up objects. Therefore, some modern TLR cameras have built-in parallax automatic compensation devices in their framing systems.

2. Compared with optical viewfinder or rangefinder, the image on ground glass is not very bright.

3. It is inconvenient to look down at the front object in a waist-flat way. Modern TLR cameras can overcome this shortcoming by adding an eye horizontal viewfinder accessory called Porro viewfinder.

4. As far as its inherent characteristics are concerned, the dual-lens system is huge, so it is necessary to replace both lenses at the same time when replacing the lenses; This is really a problem for the current large aperture fast lens.

5. The interchangeability of lenses is limited. If you change the photographic lens, you must also change the viewfinder lens. Today's TLR cameras usually provide interchangeable dual-lens devices.

6. Imaging is left and right.